classify (version 1.3)

expected.rc: Expected scores under the PCM or the GPCM.

Description

Calculates expected scores under the PCM or the GPCM.

Usage

expected.rc(beta=NULL,theta=NULL,cats=NULL,alpha=NULL)

Arguments

beta

Matrix of Beta parameters

theta

Vector of Theta parameters

cats

Vector Item category parameters

alpha

Vector of Alpha parameters (optional)

Value

Details

The beta parameters are the intersection points of adjacent category information functions. There should be one less delta parameter than categories. Assumes that the location parameter is zero. If no alpha parameters are supplied it assumes the PCM.

Examples

#One item with three categories
beta <- matrix(c(0,-1.586,-3.798),nrow=1,ncol=3)
theta <- 0.674
cats <- 3
alpha <- 1
expected.rc(beta,theta,cats,alpha)